Patent GB-873697-A (GB)
Title: Stability of polyether glycol urethane products
IPC: C08K5/00
Filed: 1958-04-10
Abstract: A method of preparing a polyurethane composition comprises reacting about 0,5 moles to about 12 moles of an organic polyisocyanate having 2 or 3 functional isocyanate groups with about one mole of a hydroxy terminated polyalkylene ether glycol having a molecular weight of at least 500, and incorporating in the product about 0,5%-5% by weight, based on the combined weight of glycol and polyisocyanate, of an antioxidant comprising an organic compound consisting only of groups which are substantially non-reactive with the isocyanate groups of the polyisocyanate and selected from the group consisting of (a) an organic phosphite of the general formula (T1O) (T2O) (T3O)P where T1, T2 and T3 are members of the group consisting of hydrogen, alkyl radicals containing at least three carbon atoms, aryl radicals and alkaryl radicals, provided that when one of the T groups is hydrogen the other two T groups are selected from alkaryl, alkyl and aryl radicals, (b) an alkyl substituted hydroxy aryl compound having an alkyl group of at least three carbon atoms located at a position ortho to each hydroxyl group attached to the aryl ring structure whereby said hydroxyl groups are sterically hindered from reaction with isocyanate, and (c) an N, N1-dialkyl substituted phenylene diamine of the formula: <FORM:0873697/IV (a)/1> in which R and R1 are alkyl groups of at least three carbon atoms.  A polyalkylene glycol ester can be substituted for part of the polyalkylene ether glycol. The reaction can be conducted in the presence of a tertiary amine catalyst and water to give a foamed product or a prepolymer can be prepared in the presence of the antioxidant for subsequent foaming. Foaming can also be produced by distributing carbon dioxide or a "Freon" (Registered Trade Mark) gas in the reaction mixture or by the action of lithium aluminium anhydride.  Coating materials and solid rubber can also be produced by the process.  Naphthalene-1, 5-, tolylene, diphenyl methane, durene and hexamethylene diisocyanates are specified for the reaction.  Cross-linking materials such as triisocyanates or trimethylol propane or aliphatic or aromatic glycols can also be employed.  In typical Examples (2) a foam is obtained by reacting polypropylene ether glycol and mixed 2, 4- and 2, 6-toluene diisocyanates in the presence of tri(nonylphenyl) phosphite to give a prepolymer which is foamed by adding silicone oil, N, N, N1, N1-tetrakis (2-hydroxy-propyl) ethylene diamine, water and dibutyl-aminoethanol; (3) films are prepared from solutions in a mixture of methyl ethyl ketone, cyclohexanone and toluene of a mixture of polytetramethylene ether glycol, 2, 4- and 2, 6-toluylene diisocyanates, N-methylmorpholine and a triisocyanate from tolylene diisocyanate and trimethylol propane, tricresyl phosphite and tributyl phosphite being added to separate portions.  Other examples illustrate the use of N, N1-disecondary octyl or butyl-p-phenylene diamines, 2, 5-ditertiary butyl para cresol, 2, 21-methylene bis-(4-ethyl-6-ter-butyl phenol, 2, 5-ditertiary butyl hydroquinone, and 4-methyl-6-ter-butyl phenol.  Dimethyl laurylamine is specified as an alternative catalyst and a white pigment and calcium carbonate as fillers.  In comparison experiments there are given results obtained when the rubber antioxidants mono-tertiary butyl hydroquinone, hydroquinone, 3, 4, 5-tris-(a -methylbenzyl) phenol, diphenylamine, p, p1-diamino diphenyl methane, meta-toluene diamine and p-phenyl phenol are used in place of the specified antioxidants.ALSO:A method of preparing a polyurethane composition which may be a foam comprises reacting about 0,5 moles to about 12 moles of an organic polyisocyanate having 2 or 3 functional iscocyanate groups with about one mole of a hydroxy terminated polyalkylene ether glycol having a molecular weight of at least 500, and incorporating in the product about 0,5 to 5% by weight, based on the combined weight of glycol and polyisocyanate, of an antioxidant comprising an organic compound consisting only of groups which are substantially non-reactive with the isocyanate groups of the polyisocyanate and selected from the group consisting of (a) an organic phosphite of the general formula (T1O) T2O) (T3O)P where T1, T2 and T3 are members of the group consisting of hydrogen, alkyl radicals containing at least three carbon atoms, aryl radicals and alkaryl radicals, provided that when one of the T groups is hydrogen the other two T groups are selected from alkaryl, alkyl and aryl radicals, (b) an alkyl substituted hydroxy aryl compound having an alkyl group of at least three carbon atoms located at a position ortho to each hydroxyl group attached to the aryl ring structure whereby said hydroxyl groups are sterically hindered from reaction with isocyanate, and (c) an N, N1 -dialkyl substituted phenylene diamine of the formula <FORM:0873697/V/1> in which R and R1 are alkyl groups of at least three carbon atoms.  A polyalkylene glycol ester can be substituted for part of the polyalkylene ether glycol.  The reaction can be conducted in the presence of a tertiary amine catalyst and water to give a foamed product or a prepolymer can be prepared in the presence of the antioxidant for subsequent foaming. Foaming can also be produced by distributing carbon dioxide or a "Freon" (Registered Trade Mark) gas in the reaction mixture or by the action of lithium aluminium anhydride.  Coating materials and solid rubber can also be produced by the process.  Naphthalene-1, 5-, tolylene, diphenyl methane, durene and hexamethylene diisocyanates are specified for the reaction.  Cross-linking materials such as triisocyanates or trimethylol propane or aliphatic or aromatic glycols can also be employed.  In a typical example (2) a foam is obtained by reacting polypropylene ether glycol and mixed 2, 4- and 2, 6-toluene diisocyanates in the presence of tri(nonylphenyl) phosphite to give a prepolymer which is foamed by adding silicone oil, N, N, N1, N1 - tetrakis (2-hydroxypropyl) ethylene diamine, water and dibutylaminoethanol.  Other examples illustrate the use of N, N1-disecondary octyl or butyl -p-phenylene diamines, 2, 5-ditertiary butyl para cresol, 2, 21-methylene bis-(4-ethyl-6-terbutyl phenol, 2, 5-ditertiary butyl hydroquinone, and 4-methyl-6-terbutyl phenol.  Dimethyl laurylamine is specified as an alternative catalyst and a white pigment and calcium carbonate as fillers.  In comparison experiments there are given results obtained when the rubber antioxidants mono-tertiary butyl hydroquinone, hydroquinone, 3, 4, 5-tris-(a -methylbenzl) phenol, diphenylamine, p, p1-diamino diphenyl methane, meta-toluene diamine and p-phenyl phenol are used in place of the specified antioxidants.